This invention relates to spacers for positioning carrier pipe within an outer casing pipe, and more particularly to improved casing spacers having a plurality of interchangeable risers for holding the carrier pipe at a desired position within the outer casing pipe.
In piping systems, an outer casing pipe is often utilized as a raceway or conduit through which is inserted a plurality of carrier pipes. The casing pipe serves to insulate and protect the carrier pipes from external environmental forces and thus prolongs the serviceability of the carrier pipes. Casing spacers are used to keep the carrier pipes in a desired position or alignment within the casing pipe, or in the case of gravity flow lines, maintain the carrier pipe at a desired grade or position along the length of the casing pipe.
Conventional casing spacers typically are comprised of a band that is secured, by bolting or other means, around the carrier pipe. Attached to the band is a plurality of risers or supports that extend outward from the surface of the band and, when the casing spacer is mounted to a carrier pipe, the carrier pipe itself. These casing spacers are placed at desired locations along the carrier pipe running within the casing pipe to support the carrier pipe within the casing.
Casing spacers are typically manufactured with bands of pre-determined sizes to fit around a desired sized carrier pipe. These bands typically have permanently fixed risers of a specified length to conform to the size of the casing pipe through which the carrier pipe is inserted. Suppliers and contractors must stock casing spacers having a variety of bands in different sizes, each having risers of a certain height, in order to accommodate the variety of carrier pipe diameters and casing pipe diameters that might be utilized on a job site. This increases the cost of maintaining a casing spacer inventory and thus the cost of construction and installation of the piping systems.
Applicants"" invention provides a casing spacer and method of use that reduces the number of different sizes of casing spacers that must be maintained to accommodate different sized carrier pipes and casing. The invention is comprised of a plurality of casing spacers each casing spacer being comprised of a band or belt that is secured around a carrier pipe by bolting, clamping, straps or other securing means. Each band or belt has a plurality of risers extending radially outward from the bands. The risers rest on the internal wall of the casing pipe, provide support for the carrier pipe and maintain the carrier pipe at a desired spacing from the wall of the casing pipe. The risers of Applicants"" invention are readily attachable and detachable from the bands. This allows a user to select a riser of a desired length and configuration.
Applicants"" invention will allow a user to maintain an inventory of bands to accommodate a selected range of pipe sizes and a range of risers in varying dimensions. Each of the risers of Applicants"" invention may be mounted to any one of the bands in the user""s inventory to form a casing spacer of a desired configuration. The user will be able to reduce the number of different casing spacers that must be maintained in the user""s inventory of casing spacers, and consequently the cost of maintaining an inventory of casing spacers. Use of the casing spacers of Applicants"" invention will also allow for rapid field adjustments to be made and thus reduce the time and costs of field changes during pipeline construction.
Because the bands used to form the casing spacers of Applicants"" invention are adapted to receive risers of a desired length to form a casing spacer of a specified dimension, the casing spacers of Applicants"" invention are particularly suitable for use in adjusting the grade of a gravity flow carrier pipe such as a sewer pipe. The fall or rise of the carrier pipe may be adjusted simply by fitting each of the bands of Applicants"" casing spacer with risers of a selected length. By using a plurality of casing spacers with risers of a desired graduated length, the pipeline can then be adjusted to a desired grade by selectively arranging the casing spacers along the length of the pipeline to position and support the carrier pipe at a desired slope or grade.
The risers of Applicants"" casing spacer can also be adapted to be readily attachable to the risers or bands of a second casing spacer that is supporting another carrier pipe. Use of such risers with the bands of Applicants"" casing spacer will allow for multiple carrier pipes to be arranged and fixed in a desired position within a single casing pipe. Thus, combinations of carrier piping and other conduit may be conveniently located during construction.
It will be seen that other uses and features of the present invention will be apparent from the following detailed description of Applicants"" invention.